Don't trust provided streams.
Return with error when stream count is not 1 or
provided stream is not an audio stream.
Signed-off-by: Lukasz Marek <lukasz.m.luki@gmail.com>
static av_cold int audio_write_header(AVFormatContext *s1)
{
AlsaData *s = s1->priv_data;
- AVStream *st;
+ AVStream *st = NULL;
unsigned int sample_rate;
enum AVCodecID codec_id;
int res;
+ if (s1->nb_streams != 1 || s1->streams[0]->codec->codec_type != AVMEDIA_TYPE_AUDIO) {
+ av_log(s1, AV_LOG_ERROR, "Only a single audio stream is supported.\n");
+ return AVERROR(EINVAL);
+ }
st = s1->streams[0];
+
sample_rate = st->codec->sample_rate;
codec_id = st->codec->codec_id;
res = ff_alsa_open(s1, SND_PCM_STREAM_PLAYBACK, &sample_rate,